# Examples for 8th grade - page 3

- Percent calculation

Calculate 22% if 68% is 42. - Trapezoid

Are diagonals in a rectangular trapezoid perpendicular and bisect the angles? - Road

Between cities A and B is route 3 km long of rise average 4‰. Calculate the height difference of cities A and B. - Painter Pavel

Painter Pavel painted the fence for 20 hours and painter Petr the same fence painted for 17 h. How long should take painted the fence together? - KLMN

In the trapezoid KLMN is given this informations: 1. segments KL and MN are parallel 2. segments KL and KM has same length 3. segments KN, NM and ML has same length. Determine the size of the angle KMN. - Right Δ

Right triangle has length of one leg 7 cm and length of the hypotenuse 25 cm. Calculate the height of the triangle. - Cylinder - h

Cylinder volume is 129 cm^{3.}Base radius is 3 cm. Calculate the height of the cylinder. - Center traverse

It is true that the middle traverse bisects the triangle? - Christmas Day

In leap years was 53 Sundays. On what day of the week fell to Christmas Day? - Workers

Two workers fulfill a certain task when working together for 7 days, the first if he worked himself done work in 18 days. How many days will do whole job a second worker? - AVG of INT

What is the average of the integers from 7 throuht 15 inclusive? - Beer

After three 10° beers consumed in a short time there are 7.4 g of alcohol in 5 kg adult human blood. How much is it per mille? - Coin and die

Flip a coin and then roll a six-sided die. How many possible combinations are there? - Diofant 2

Is equation ? solvable on the set of integers Z? - MO SK/CZ Z9–I–3

John had the ball that rolled into the pool and it swam in the water. Its highest point was 2 cm above the surface. Diameter of circle that marked the water level on the surface of the ball was 8 cm. Determine the diameter of John ball. - Diagonal

Calculate the length of the diagonal of the rectangle ABCD with sides a = 7 cm, b = 6 cm. - Chickens and rabbits

In the yard were chickens and rabbits. They had 44 heads and 124 legs. How many chickens and how many rabbits was in the yard? - Ladder

Ladder 5 m long is leaning against the wall. It foot is 0.9 m away from the wall. In which height ladder touch the wall? - Saving

Kevin save € 4620 to buy a car. Yet it lacks save 65% of the car price. How much is the car? - Number

Is number 4.764023 irrational?

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